What Happens If You Don’t Sleep? A Teen Went 11 Days

What happens if you don’t sleep? Hour by hour, here’s what sleep deprivation does to your brain and body, and the one thing you may never notice.

Most of us have pulled an all-nighter and survived, but sleep isn’t just downtime. In this video, we break down what happens when you don’t sleep, from the first 24 hours of impaired attention and judgment to what researchers say can happen after 48 hours and 3 days awake, and what the longest recorded attempt can teach us.

We walk through the sleep deprivation stages and the effects of sleep deprivation on the brain and body: the studies comparing a day awake to being legally drunk, why memory can become badly impaired around 36 hours, how the immune system may be affected, and why sleep deprivation hallucinations and distorted perception can show up after about 72 hours. We also explain why we need sleep in the first place, including how the brain clears waste while you rest, and look at the famous case of Randy Gardner, who stayed awake for about 11 days in 1964 under the watch of sleep researchers.

The big reveal is something your brain does that you can’t feel and often never notice, and it’s the reason sleepy driving is so dangerous. If you’ve ever wondered what happens to your body when you don’t sleep, or what happens if you don’t sleep for 24 hours, this video lays out what the research suggests, and where the evidence runs thin.

What’s the longest you’ve ever stayed awake, and what’s the weirdest thing your brain did? Tell us in the comments, and subscribe for more science explained in plain language. If you’re regularly struggling to sleep, it’s worth talking to a doctor.